Historically, incandescent lights with filament-type bulbs have been a popular light source. Incandescent light bulbs illuminate radially outward and the illumination is distributed approximately uniformly in all directions. Fluorescent lights with fluorescent circular tubes have been an alternative to incandescent lights because of their energy-efficient qualities.
LED bulbs are light sources that use semiconductor materials rather than filaments or gasses to emit light. LED bulbs are generally more efficient light sources than incandescent, light bulbs because LED bulbs are nearly monochromatic and emit light within a very narrow range of wavelengths. LED bulbs also generally last many times longer than incandescent light bulbs or fluorescent light sources.